"Sheriff's Detectives are working with the Federal Bureau of Investigation (FBI), Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) and Escondido Police Department to check Earnest's possible involvement in the arson and vandalism of a mosque in Escondido on 24 March", Gore said in a statement.
The statement comes after a 19-year-old man, identified as John T. Earnest, opened fire on Saturday at a synagogue in the California city of Poway, located in the vicinity of San Diego. The attack left one person dead and three others injured, including the synagogue's rabbi and a young girl. Poway Mayor Steve Vaus has deemd the incident a hate crime. The shooter was later detained.
An internet user, who called himself John T. Earnest, posted an open anti-Semitic letter mere hours ahead of the attack on the synagogue. The author of the letter said that he was "inspired" by Robert Bowers, who staged a shooting at a synagogue in Pittsburgh last November that killed 11 people, and Brenton Tarrant, who shot dead 50 people in mosques in Christchurch, New Zealand on 15 March.